import java.util.Arrays;
import java.util.Random;
import java.util.Scanner;

/*
public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int a = scan.nextInt();
        int count=1;
        int c=a;
        int sum=0;
        while (c/10!=0){
            c/=10;
            count++;
        }
        int[]array=new int[count];
        for (int i=0;i<count;i++) {
            array[i]=a%10;
            a/=10;
        }
        if (array[0]!=0){
            System.out.print(array[0]);
            sum+=array[0];
        }
        for (int i=1;i <count;i++) {
            if(sum!=0){
                System.out.print(array[i]);
            }
            else {
                if(array[i]!=0){
                    sum+=array[i];
                    System.out.print(array[i]);
                }
            }
        }

    }
}*/
/*
public class Main {
    public static void main(String[] args) {
        Scanner scan=new Scanner(System.in);
        int a= scan.nextInt();
        int c=a;
        int b=1,count=1,sum=0,n=0;
        while (c/10!=0){
            c/=10;
            count++;
        }
        while (count>1){
            b*=10;
            count--;
        }
        while (a/10!=0){
            n=a%10;
            sum+=n*b;
            a/=10;b/=10;
        }
        System.out.println(sum+=a*b);
    }
}*/
/*
public class Main {
    public static void main(String[] args) {
        Scanner scan=new Scanner(System.in);
        int a= scan.nextInt();
        int r=0,d=0;
        while (a>0){
            d=a%10;
            r=r*10+d;
            a/=10;
        }
        System.out.println(r);
    }
}*/
/*
public class Main {
    public static void main(String[] args) {
        int[]array=new int[10];
        Scanner scan=new Scanner(System.in);
        for(int i=0;i< array.length;i++){
            array[i]= scan.nextInt();
        }
        for(int i=0;i< array.length-1;i++){
                boolean a=false;
            for(int j=0;j< array.length-1-i;j++){
                if(array[j]>array[j+1]){
                    int tmp=array[j];
                    array[j]=array[j+1];
                    array[j+1]=tmp;
                    a=true;
                }
            }
            if(a==false){
                break;
            }
        }
        String b=Arrays.toString(array);
        System.out.println(b);
    }
}*/
public class Main {
    public static void main(String[] args) {
        Scanner scan=new Scanner(System.in);
        int a= scan.nextInt();
        Random random=new Random();
        char[]array=new char[a];
        for (int i = 0; i <a; i++) {
            String n=random.nextInt(2)%2==0?"char":"num";
            if("char".equals(n)){
                int choice1=random.nextInt(2)%2==0?65:97;
                array[i]=((char)(random.nextInt(26)+choice1));
            }
            else {
                int choice2=random.nextInt(10);
                array[i]=((char)(choice2+48));
            }
        }
        for (int j =0;j<a;j++) {
            System.out.print(array[j]);
        }
    }
}//随机生成一个长度为8-20个字符的密码字符序列（长度可由用户指定），其中要包含大小写字母及数字，结果放入字符数组内并显示